1. Field of the Invention
The present invention relates to a printing apparatus, printing system, and a printed material manufacturing method.
2. Description of the Related Art
With respect to high-speed printing, it is difficult to increase a printing speed in a shuttle system which is a mainstream of a current inkjet recording system, and therefore a single-pass system using a page-width line head has been proposed. However, although the single pass system is advantageous to the printing speed, a time interval between dropped adjacent dots is short, and an adjacent dot is dropped before previously dropped ink penetrates into a printing medium. Therefore, coalescence of the adjacent dots (called “droplet interference”) occurs, which results in occurrence of beading, bleeding, or the like, and this may cause image quality to degrade.
There is also a problem that when an inkjet printing apparatus prints an image on non-permeable media or on slow-permeable media, such as a film or a coated paper, adjacent ink dots move to coalesce, which causes an image defect such as beading or bleeding.
Conventionally, therefore, a printing speed is reduced and a drying device is installed in order to overcome the weakness of a plain paper and a coated paper. In addition, there is a method of previously applying a primer liquid to the printing medium in order to improve a setting property of aqueous ink.
As other method of improving the setting property of the aqueous ink, a method of performing a plasma treatment on the surface of a printing medium is proposed. It is known that the plasma treatment is performed to hydrophilize the surface of the printing medium. Therefore, the performance of the plasma treatment can improve a hydrophilic property and a permeability of a coated paper with poor wettability. Furthermore, the plasma treatment is a drying process, and therefore it is advantageous that the drying process is not necessary.
Therefore, there is a need to provide a printing apparatus, a printing system, and a printed material manufacturing method capable of appropriately using inks having different properties such as pH reaction.